TY  - JOUR
A1  - Amatobi, Kelechi M.
A1  - Ozbek-Unal, Ayten Gizem
A1  - Schäbler, Stefan
A1  - Deppisch, Peter
A1  - Helfrich-Förster, Charlotte
A1  - Mueller, Martin J.
A1  - Wegener, Christian
A1  - Fekete, Agnes
T1  - The circadian clock is required for rhythmic lipid transport in Drosophila in interaction with diet and photic condition
JF  - Journal of Lipid Research
N2  - Modern lifestyle is often at odds with endogenously driven rhythmicity, which can lead to circadian disruption and metabolic syndrome. One signature for circadian disruption is a reduced or altered metabolite cycling in the circulating tissue reflecting the current metabolic status. Drosophila is a well-established model in chronobiology, but day-time dependent variations of transport metabolites in the fly circulation are poorly characterized. Here, we sampled fly hemolymph throughout the day and analyzed diacylglycerols (DGs), phosphoethanolamines (PEs) and phosphocholines (PCs) using LC-MS. In wild-type flies kept on sugar-only medium under a light-dark cycle, all transport lipid species showed a synchronized bimodal oscillation pattern with maxima at the beginning and end of the light phase which were impaired in period01 clock mutants. In wild-type flies under constant dark conditions, the oscillation became monophasic with a maximum in the middle of the subjective day. In strong support of clock-driven oscillations, levels of the targeted lipids peaked once in the middle of the light phase under time-restricted feeding independent of the time of food intake. When wild-type flies were reared on full standard medium, the rhythmic alterations of hemolymph lipid levels were greatly attenuated. Our data suggest that the circadian clock aligns daily oscillations of DGs, PEs, and PCs in the hemolymph to the anabolic siesta phase, with a strong influence of light on phase and modality.
KW  - hemolymph lipids
KW  - lipidomics
KW  - circadian rhythm
KW  - feeding
KW  - locomotor activity
KW  - light-driven metabolism
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-349961
VL  - 64
IS  - 10
ER  - 
TY  - JOUR
A1  - Fujiwara, Yuri
A1  - Hermann-Luibl, Christiane
A1  - Katsura, Maki
A1  - Sekiguchi, Manabu
A1  - Ida, Takanori
A1  - Helfrich-Förster, Charlotte
A1  - Yoshii, Taishi
T1  - The CCHamide1 Neuropeptide Expressed in the Anterior Dorsal Neuron 1 Conveys a Circadian Signal to the Ventral Lateral Neurons in Drosophila melanogaster
JF  - Frontiers in Physiology
N2  - The fruit fly Drosophila melanogaster possesses approximately 150 brain clock neurons that control circadian behavioral rhythms. Even though individual clock neurons have self-sustaining oscillators, they interact and synchronize with each other through a network. However, little is known regarding the factors responsible for these network interactions. In this study, we investigated the role of CCHamide1 (CCHa1), a neuropeptide expressed in the anterior dorsal neuron 1 (DN1a), in intercellular communication of the clock neurons. We observed that CCHa1 connects the DN1a clock neurons to the ventral lateral clock neurons (LNv) via the CCHa1 receptor, which is a homolog of the gastrin-releasing peptide receptor playing a role in circadian intercellular communications in mammals. CCHa1 knockout or knockdown flies have a generally low activity level with a special reduction of morning activity. In addition, they exhibit advanced morning activity under light-dark cycles and delayed activity under constant dark conditions, which correlates with an advance/delay of PAR domain Protein 1 (PDP1) oscillations in the small-LNv (s-LNv) neurons that control morning activity. The terminals of the s-LNv neurons show rather high levels of Pigment-dispersing factor (PDF) in the evening, when PDF is low in control flies, suggesting that the knockdown of CCHa1 leads to increased PDF release; PDF signals the other clock neurons and evidently increases the amplitude of their PDP1 cycling. A previous study showed that high-amplitude PDP1 cycling increases the siesta of the flies, and indeed, CCHa1 knockout or knockdown flies exhibit a longer siesta than control flies. The DN1a neurons are known to be receptive to PDF signaling from the s-LNv neurons; thus, our results suggest that the DN1a and s-LNv clock neurons are reciprocally coupled via the neuropeptides CCHa1 and PDF, and this interaction fine-tunes the timing of activity and sleep.
KW  - circadian clock
KW  - circadian rhythm
KW  - CCHamide1
KW  - pacemaker neuron
KW  - neuropeptide
KW  - pigment-dispersing factor
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195940
SN  - 1664-042X
VL  - 09
ER  -